Upgrade GPU or CPU?

[OneSaltyDog]

So I have a dilemma, and I would like some advice from more experienced gamers. I currently have 2 gaming computers right now,

but I am going to sell one of them to upgrade my main one, but I am not sure which upgrade path to take as I can only afford one most likely

Computer 1)

Case- Corsair spec-03

Video Card-strix gtx 960 2gb
Cpu-fx-6300 non oc

Mobo-asus r5a97 R2.0

Psu- corsair cx750

Hdd-1tb seagate, 120gb ssd

Ram-8gb ddr3

 

Computer 2)

Case- Nzxt Phantom

Video Card- XFX 7970 3gb
Cpu- fx-8150

Mobo- Crosshair v formula

Psu- XFX 1000w platinum 80+

Hdd- 2tb wd black, 60gb ssd

Ram-12gb ddr3

Fan Controller-NZXT sentry lx

What I want to do piece together with all my parts the best specs, sell the other one for as much as i can, (around $450-650)

and what I want to buy is either the new gtx 1080/70 or a 6700k bundle, but I cant decide which route to go as both would

be bottlenecks. So i have 2 questions, What part configuration should I keep, and how much should I sell the other for?

And when I get the money should I got for a gtx 1080 or 1070, or Should i buy a 6700k with a new mobo and 8gb ddr4?

Thankyou and any help is appreciated

 

Both would come out to around $400

[BingoFishy]

Your processor would certainly bottleneck a 1080. You may want  to go for a 6500 or 6600k and a 1070. It will provide better performance than one of the above alone.

[Kinda Bottlenecked]

I think you can get an i5 6600K + new mobo + DDR4 RAM first. You'd have somthing like this:

 

Case- Nzxt Phantom

Video Card- XFX 7970 3gb
Cpu- i5 6600K

Mobo- (Whichever LGA 1150 Mobo you choose)

Psu- XFX 1000w platinum 80+

SSD- 120GB

HDD1- 2TB WD

HDD2- 1TB Seagate

Ram- (Whichever DDR4 ram you choose)

Fan Controller-NZXT sentry lx

 

And sell everything else. The 7970 should tide you over for the time being until you get a next gen gpu. You can go the i7 6700K CPU as well if you wish to.